Sarcopenia is the scientific term for muscle wasting. Most of us don’t pay attention to the loss of muscle until we are well up in years, in our late 60s or early 70s, but muscle loss begins much earlier in life.

When we think about things that give us the appearance of being old, we think in terms of gray hair, stooped posture and false teeth, but one of the main things is the gradual loss of muscle and the accumulation of body fat.

We also tend to ignore the loss of muscle unless we are called upon to exert our strength and cannot meet the demands. But there is more to muscle loss than just losing strength.

In the younger adult body, muscle is the most prevalent tissue, representing approximately 40 percent of the total body mass. Muscle is “hungry” tissue and burns most of the calories your body uses for energy. As muscle is lost, metabolism decreases and you burn fewer calories.

In turn, if you continue to consume the same number of calories, you will gain body fat. Increased fat, especially around the midsection, is associated with a flock of medical problems, including diabetes, hypertension, heart disease and stroke.

Muscle mass is tied to bone health. Bones are healthier when they are subjected to regular stress. Weight-bearing exercise and the tugging and pulling of muscle tendons on bones during exercise is good for them and encourages them to store more calcium. Reduce stress on bones and they lose calcium and become weaker. In the extreme, this is called osteoporosis.

Recently, I wrote about how the elderly are more prone to falling. Often, this is because of lost muscle mass and strength, which reduces the ability to instantly respond to a challenge to one’s balance.

Mother Nature’s role

Losing muscle mass is not entirely our fault. A vigorous lifestyle and resistance exercise can delay the onset of muscle loss and can reduce the loss over time, but Mother Nature makes certain that some degree of loss will occur no matter what.

Within muscle cells, there is a natural slowdown in metabolic activity. The muscles are not able to synthesize muscle proteins as well when we get older, which is critical, because protein is the primary structure in muscle.

Older cells in the body are always being replaced by younger and more vibrant cells. When we are young, the production of new cells outstrips the removal of old ones, and that’s how we grow and develop. At maturity, there is a balance between production and destruction, and we tend to maintain the status quo. When we get older, the tearing-down process begins to outpace production, and we end up with a net loss of muscle that gets worse year by year.

Hormone production declines with age, especially testosterone, and hormones are important stimulants for growing muscle tissue. And as we age, we lose nerve cells. Muscles can’t work without being stimulated by nerves, and fewer nerve cells mean less muscle stimulation.

The gender impact is a cruel irony. Women start with less muscle mass and strength, and thus have a smaller margin of error than men when it comes to the implications of muscle loss. However, women live longer than men, and as the men in their lives are lost, older women often live alone. This creates more demand for muscle mass and strength at a time when the loss of both is accelerating.

The same circumstances are found in bones. Women have smaller and weaker bones that contain less calcium. With age, calcium is lost in increasing amounts, and when too much is lost, the bones weaken to the point where they can no longer do their job. Weak bones break in critical places, like the hip joint, and this is often the cause of falls.

The bottom line

No matter what you do, there is an inevitable loss of muscle mass and strength with age. However, a healthy lifestyle that emphasizes resistance training can offset such losses to a large degree. I’ll discuss the impact of lifestyle next week.

This archive contains all the stories that appeared on the Tucson Citizen's website from mid-2006 to June 1, 2009.

In 2010, a power surge fried a server that contained all of videos linked to dozens of stories in this archive. Also, a server that contained all of the databases for dozens of stories was accidentally erased, so all of those links are broken as well. However, all of the text and photos that accompanied some stories have been preserved.

For all of the stories that were archived by the Tucson Citizen newspaper's library in a digital archive between 1993 and 2009, go to Morgue Part 2